Hello MattVanExcellent,
Thanks for reaching out to the Apple Support Communities. We understand you are experiencing issues receiving notifications for messages on your iPhone. We are happy to help provide some guidance.
To start, we want to make sure that notifications are set properly for messages as well as your volume and Do Not Disturb settings are set properly. Take a look at the following resources that go over making sure that notifications are enabled for Messages and your volume is set properly:
Use notifications on your iPhone, iPad, and iPod touch
If you hear no sound or distorted sound from your iPhone, iPad, or iPod touch speaker
Additionally, we would want to make sure that your iPhone is updated with the latest iOS version available. Take a look at how to update your iOS version here:
Update your iPhone, iPad, or iPod touch
Keep us updated with how it goes or if you have any questions.
Best Regards.